Corpuscles.jl
Corpuscles.jl is a package which gives easy access to particle properties and identification codes summarised and defined by the Particle Data Group (PDG) collaboration. The cleaned CSV versions of these data are provided by courtesy of the Scikit-HEP project and are part of the Particle Python module which inspired us to create a similar package for the Julia Language. Corpuscles.jl is by far not as feature complete as Particle, but we add functionality continuously, as needed. Feel free to create an Issue or pull request if you find any bugs or have suggestions to improve.
Usage
The Particle struct can be used to create a particle. If an integer value is
passed, it will be interpreted as PDG ID, which is the primary particle
encoding in Corpuscles.jl:
julia> using Corpuscles
julia> p = Particle(12)
Particle(12) 'nu(e)'To get an overview of the available particle information, use print():
julia> print(p)
Name: K(4)*(2045)
PDG ID: -319
LaTeX: $\bar{K}_{4}^{*}(2045)^{0}$
Status: Common
Width = 198.0 MeV ± 30.0 MeV
Q (charge) = 0//1 e
Composition = Ds
Isospin = 1//2
Mass = 2045.0 MeV ± 9.0 MeV
P (space parity) = 1The properties are accessible via attributes:
julia> fieldnames(Particle)
(:pdgid, :mass, :width, :charge, :isospin, :parity, :gparity, :cparity, :antiprop, :rank, :status, :name, :quarks, :latex)
julia> p.quarks
"Ds"
julia> p.isospin
1//2
julia> p.mass
2045.0 MeV ± 9.0 MeVThere are tons of helper functions to check other properties:
julia> filter(hasstrange, particles())
257-element Array{Particle,1}:
Particle(3224) Sigma(1385)
Particle(23124) Lambda(1890)
Particle(-13324) Xi(1820)
Particle(-329) K(4)*(2045)
⋮
Particle(13124) Lambda(1690)
Particle(-100321) K(1460)
Particle(20433) D(s1)(2460)
julia> filter(islepton, particles())
16-element Array{Particle,1}:
Particle(18) nu(tau')
Particle(15) tau
Particle(11) e
Particle(13) mu
Particle(14) nu(mu)
Particle(17) tau'
⋮
Particle(12) nu(e)
Particle(-14) nu(mu)
Particle(-16) nu(tau)
Particle(-12) nu(e)
Particle(-13) muUnits
For some properties like mass and width we use the
Unitful package, which makes it
easy to combine values with physical units:
julia> typeof(p.mass)
Corpuscles.MeasuredValue{𝐋^2 𝐌 𝐓^-2}
julia> p.mass
2045.0 MeV ± 9.0 MeV
julia> p.mass.value
2045.0 MeV
julia> p.mass.lower_limit
9.0 MeV
julia> p.mass.upper_limit
9.0 MeVand also Base.isless and Base.isapprox are implemented so that the
lower and upper limits are taken into account, as seen here:
julia> using Unitful
julia> p.mass
2045.0 MeV ± 9.0 MeV
julia> p.mass > 2036u"MeV"
false
julia> p.mass > 2035u"MeV"
trueParticle Codes
Corpuscles currently supports conversions of Pythia and Geant3 codes to PDG
using the Pythia and Geant3ID types. The corresponding number is simply
passed to the type and then to the Particle itself. The PDG ID will be
converted if possible, otherwise an error will be raised.
julia> Particle(Geant3ID(5))
Particle(-13) 'mu'Finding Particles
The particles() functions returns a Vector containing all the particles
of the currently selected catalog. To search for particles, the filter()
function comes in hand which can be combined with string comparison functions
like startswith() or occursin().
Here is an example how to find all particles with names starting with "nu":
julia> filter(p->startswith(p.name, "nu"), particles())
6-element Array{Particle,1}:
Particle(-14) 'nu(mu)'
Particle(-16) 'nu(tau)'
Particle(-12) 'nu(e)'
Particle(14) 'nu(mu)'
Particle(16) 'nu(tau)'
Particle(12) 'nu(e)'A more powerful way to filter particles based
on patterns in their name is using [regular
expressions](https://docs.julialang.org/en/v1/manual/strings/#Regular-Expressio ns-1)
with e.g. occursin():
julia> filter(p->occursin(r"D\(\d*\)", p.name), particles())
10-element Array{Particle,1}:
Particle(-10421) 'D(0)*(2300)'
Particle(-10411) 'D(0)*(2300)'
Particle(425) 'D(2)*(2460)'
Particle(10411) 'D(0)*(2300)'
Particle(10421) 'D(0)*(2300)'
Particle(10423) 'D(1)(2420)'
Particle(-425) 'D(2)*(2460)'
Particle(-10423) 'D(1)(2420)'
Particle(415) 'D(2)*(2460)'
Particle(-415) 'D(2)*(2460)'Another useful feature is the Particle(n::String, anti=false) which directly
creates a (anti-)particle from a given name -- as long as it exists in the
currently loaded particle dataset:
julia> Particle("mu") == Particle(13)
true
julia> -Particle("mu") == Particle(-13)
true
julia> Particle("anti-mu") == Particle(-13)
true
julia> Particle("mu~") == Particle(-13)
true
julia> Particle("muon") == Particle(13)
true
julia> Particle("mu-") == Particle(13)
true
julia> Particle("mu+") == -Particle(13)
true